Irrigation has been considered as one of the important keys for the maintenance of races since olden days. However, the majority of water secured by hard labor, has been returned back into the soil uselessly.
Recently, dripping methods of irrigation have been used in foreign countries where dry regions occupy the greater part of land. However, since these methods require electric power and special equipment, these methods are employed in limited places.
Miscellaneous devices have been realized since olden days in the effectual utilization of irrigated water in order to maintain the prosperity of races.
However, in order to maintain the population which is increasing day by day, the development of effective irrigated water is now keenly urged in consideration of the limited efficiency of prior irrigated water.
The dripping method of irrigation was practically used for the first time by Symcha Blazs in 1930 and has greened many deserts and barren lands.
However, since the dripping method of irrigation requires flow control equipment, electrical solenoid valves, and timers, it still has problems and troubles unavoidable in such a system and also economical burdens.